Knowing the location of a mobile communication device at any given point of time is useful and sometimes necessary information for a variety of reasons. This may be for safety reasons, or for planning next set of actions, or many other reasons. Currently, a few techniques are available to locate a mobile communication device, and/or track a path taken by the mobile communication device.
DE3827352 describe a method to determine the instantaneous location of a mobile station. Here a mobile radio station buffer receives data messages from at least 3 stationary radio stations and these are stored in a computer in the mobile station. The instantaneous location is determined by computing the propagation time differences between the transmission and reception of respective data messages which are stored in a computer in stationary radio stations.
Location can also be determined, as described in patent WO98058459, by coding the mobile communication network as a several digit number via a base station which momentarily supplies the mobile station and attaching it to the call number of the subscriber as an extension number. This extended call number is used to connect through an information centre to which a subscriber communicated through the mobile connection network. The location related information is then transmitted from the information centre to the subscriber.
U.S. Pat. No. 6,314,296 describes the use of a wireless communication apparatus which receives identification information of a wireless base station to which the apparatus is connected. The position of the base station is stored in the memory of the apparatus. The position information of the calling side can be notified to the called side.
US20090005972 provides a method to determine the location or direction of travel. According to this invention a device is located by comparing user's measured cellular transition patterns with a map that contains measured distinct characteristics of a cellular-radio signal and a model of road networks. Cellular transitions are registered when a device or a vehicle is moving through various cellular or radio networks. The sequence of transitions is used in creating a map. It is then matched with the model of road networks previously generated. Location is determined by independent measurement and cross-referenced as a function of time.
DE19721504 describes a method for position determination using GPS coordinates. Here, a mobile communications device (MS) is used as a peripheral for a positioning system, which calculates the position of the mobile communications device from the known positions of at least one (preferably three) base stations with which it is in radio communication and the relative spacing of the mobile communications device from each base station. The resulting position information is displayed at the mobile communications device. The positions of the base stations are determined via a global positioning system, the spacing of the mobile communications device from each base station determined from the propagation time of the transmitted radio signals.
A slightly different approach to determine location of a device using GPS was described in US20010018344. Here each base station is assigned a unique code. When a mobile station is interacting with a base station its code is recorded along with the position coordinates of a geographic feature as determined by GPS coordinates. The sequence of coordinates and times are used to determine the movement of data.
All the techniques described herein require sophisticated instrumentation to obtain accurate position information, or else the position information is generally inaccurate. There is still a dire need in the art to obtain position information of a mobile communication device using simple devices to a great degree of accuracy without ambiguity in a relatively inexpensive manner.